Circular knitting machine panty hose slitting device and method

ABSTRACT

Seamless tubular fabric, such as panty hose blanks, are slit in a walewise direction as they are being knit on a circular hosiery knitting machine by means of the present method and apparatus. A relatively thin hooked yarn holding dial element is supported inside of the needle circle for rotation in timed relationship with the needles therein and the hooked outer end portion is thin enough to pass between immediately adjacent knitting needles to pick up and hold the yarn as it is fed to and knit on needles positioned adjacent opposite sides thereof. Cam means is provided for imparting radial movement to the dial element to cut the held yarn loop and separate or slit the fabric as it is knit.

[ Sept. 3, 1974 CIRCULAR KNITTING MACHINE PANTY HOSE SLITTING DEVICE AND METHOD [75] Inventor: HarperShields,Burlington,N.C.

[73] ASSignee: Pilot Research Corporation,

Burlington, NC.

22 Filed: Aug. 18, 1969 21 Appl. No.: 850,943

1,302,224 7/1962 France 66/92 Primary Examiner-Ronald Feldbaum Attorney, Agent, or Firm-Parrott, Bell, Seltzer, Pa & Gibson 7] ABSTRACT Seamless tubular fabric, such as panty hose blanks, are slit in a walewise direction as they are being knit on a circular hosiery knitting machine by means of the present method and apparatus. A relatively thin hooked yarn holding dial element is supported inside of the needle circle for rotation in timed relationship with the needles therein and the hooked outer end portion is thin enough to pass between immediately adjacent knitting needles to pick up and hold the yarn as it is fed to and knit on needles positioned adjacent opposite sides thereof. Cam means is provided for imparting radial movement to the dial element to cut the held yarn loop and separate or slit the fabric as it is knit.

9 Claims, 5 Drawing Figures PATENTED I974 V 3.832.869

HARPER smws ATTORNEYS CIRCULAR KNITTING MACHINE PANTY HOSE SLITTING DEVICE AND METHOD This invention relates generally to circular hosiery knitting machines and more particularly to an apparatus and method for slitting seamless tubular panty hose blanks in a walewise direction as they are being knit on the machine. Panty hose blanks are normally knit on a fine gauge ladies type hosiery knitting machine and a walewise extending slit is subsequently formed in the upper portion of the blank before the corresponding edges of a pair of blanks are stitched together to form the panty hose garment.

Devices have been proposed for automatically carrying out this slitting operation while the blank is being knit. The apparatus heretofore proposed have required that one or more of the cylinder needles remain in a lowered or inactive position at each knitting station and during the time that the slit is being formed in the panty portion. In certain types of circular hosiery knitting machines, it is not practical to maintain one or more needles in a lower inactive position at each knitting station, without drastic modification of the knitting machine.

With the foregoing in mind, it is an object of the present invention to provide an apparatus and method for slitting tubular fabric in a walewise direction as the fabric is being knit on a circular knitting machine and wherein all of the needles in the needle cylinder continue to knit while the fabric is being slit.

The preferred embodiment of the apparatus includes a holding dial element supported inside of the needle circle and having a very thin outer hooked portion which is movable in a radial direction outwardly and inwardly between immediately adjacent cylinder needles. Fixed cutting blade members are supported adjacent opposite sides of the hooked portion of yarn holding dial element and are resiliently urged into engagement with opposite sides thereon. The yarn holding dial element includes an upstanding operating butt positioned on the inner end portion. First cam means is positioned in advance of the knitting station of the machine and is selectively operable to engage the operating butt and to thereby project the yarn holding dial element outwardly between adjacent cylinder needles to pick up and hold the yarn while it is knit on the needles immediately adjacent opposite sides thereof. Second cam means is provided subsequent to the knitting station for imparting inward radial movement to the yarn holding dial element to bring the yarn loops held in the hooked portion into engagement with fixed cutting blade members to cut the held yarn loops and slit the fabric as it is knit with each rotation of the needle cylinder.

Third cam means is provided for imparting a slight outward radial movement to the yarn holding dial element upon completion of the knitting of the slit portion of the fabric to release any yarn which may be caught or trapped in the dial element.

Some of the objects of the invention having been stated, other objects will appear as the description proceeds when taken in connection with the accompanying drawings, in which FIG. 1 is a sectional plan view of the needle circle of a multiple feed knitting machine, illustrating the yarn feeding and knitting stations and showing the operation cams for the dial element in cross-section;

FIG. 2 is an isometric fragmentary view of the main yarn feeding station and illustrating the manner in which the hooked outer end portion of the dial element is projected outwardly and between immediately adjacent active needles to pick up a yarn loop therein;

FIG. 3 is a fragmentary isometric view of a portion of the dial plate, illustrating the manner in which the radially movable dial element and the fixed cutting blades are supported therein;

FIG. 4 is a greatly enlarged fragmentary plan view of the portion of the dial plate surrounding the dial element and illustrating the manner in which the fixed cutter blades are resiliently urged against opposed sides of the dial element; and

FIG. 5 is a side elevational view of the outer portion of the dial element and the adjacent fixed blade element.

The slitting device of the present invention is illustrated in use on a fine gauge circular hosiery knitting machine of the type known as a Singer-Fidelity fourfeed knitting machine. However, it is to be understood that the slitting device of this invention may also be utilized with other types of circular knitting machines having a single or multiple yarn feeding and knitting stations.

The circle of needles N normally moves in a counterclockwise direction during rotary knitting and the needles are supported in the usual manner in vertical slots in a needle cylinder, not shown. The machine is provided with the usual stitch cams which are supported beneath the yarn knitting stations, indicated at 10, 11, 12 and 13 (FIG. 1). The knitting station 10 is usually referred to as main knitting station and normally includes more yarn feed fingers, of the type indicated at 15, thanthe remaining knitting stations. The other knitting stations 11-13 are usually referred to as auxiliary knitting stations and usually have several yarn feed fingers. Only one yarn feed finger is shown at each knitting station ll-13 and they are indicated at 16, 17, and 18, respectively.

During rotation of the circle of needles N, body yarns B4, B-2, B-3 and 8-4 are fed to the hooks of the needles at the respective knitting stations 10-13 and stitch loops are formed in the conventional manner so that the machine forms four courses with each rotation of the needle circle. The yarn feed fingers 15-18 are supported for movement into and out of knitting position, in the conventional manner, so that the machine may knit in a single or multiple feed manner, if desired. As best shown in FIG. 2, the needles N are raised as they approach the knitting station to pick up the yarn in their hooks as it is fed from the yarn feed finger 15. The needles are then lowered to stitch forming level to form a new stitch loop as the previously formed stitch loop closes the latch and is cast therefrom.

In accordance with the present invention, a substantially smooth dial plate 20 is supported for rotation beneath the dial cap, not shown, which supports suitable cams, to be presently described. The dial plate 20 is rotated by means of a drive shaft 21 which extends upwardly and is drivingly connected through suitable drive gears to the needle cylinder drive so that the dial plate 20 moves in scnchronization with movement of the needle cylinder and the circle of needles N. The outer portion of the dial plate 20 is provided with a thickened annular outer portion which is provided with a radial groove 22. The outer portion of the groove 22 is curved outwardly and widened, as at 22a (FIGS. 3 and 4) and extends outwardly to the outer peripheraledge of dial plate 20.

A yarn engaging and holding dial element, broadly indicated at D, is supported for radial sliding movement in the groove 22 of the dial plate and includes a relatively thick inner body portion 24 and a relatively thin outer hooked portion 25. The outer end of the hooked portion 25 is beveled on opposite sides to form a sharpened outer terminal end 26 to aid in passage of the hooked portion 25 outwardly between immediately adjacent needles N, in a manner to be presently described.

A dial cap, not shown, supports an inner cam ring 29 and an outer cam ring 30 (FIG. 1) which operate to guide an upstanding operating butt 31 on the inner body portion 24 of the dial element D. The inner cam ring 29 is provided with an outwardly projecting fixed cam portion 32 which is provided to at times impart a slight outward movement to the dial element D, for purposes to be presently described. The outer cam ring 30 is provided with an inwardly projecting fixed cam portion 33 which is adapted to impart an inward inlet movement to the dial element D and to thereby cut any held loops thereon, in a manner to be presently described. The cam portion 33 forms a part of a yarn cutting means which is located between the last yam knitting station l3 and the first or main knitting station 10.

An operating cam 34 is supported for vertical movement between the inner cam ring 29 and the outer cam ring 30 and may be raised to an inoperative position and lowered to an operative position by suitable linkage, not shown, which is controlled by any suitable pattern mechanism on the knitting machine. The cam 34 moves downwardly into the operative solid position shown in FIG. I to engage the butt 31 and move the dial element D outwardly between immediately adjacent needles N so that its outer hooked end remains in position to pick up and form a held loop of yarn as adjacent needles are drawn down to stitch forming level at the knitting station. In the present instance, the cam 34 will be referred to the first cam means, the cam 33 as the second cam means, and the cam 32 as the third cam means.

A pair of yarn cutting blade elements 40, 41 are fixedly supported at their inner ends in the radial groove 22 and in sliding relationship with opposite sides of the thickened body portion 24 of the dial element D. The outer end portions of the cutting blades are bent downwardly and then inwardly (FIG. 4) so that the outer terminal ends are resiliently urged against opposite sides of the thin hooked portion 25 of the dial element D. The outer terminal portions of the blades 40, 41 are beveled to provide respective cutting surfaces a, 410 against which a held yarn loop is drawn by the hooked outer portion 25 to cut any held yarn loops therein, as the dial element D is drawn inwardly. The fixed cutting .blade elements 40, 41 are formed of very thin material and the outwardly bent outer end portions engage the opposed walls of the widened portion 220 of the slot 22 so that the cutting surfaces 4011. Ma are resiliently urged inwardly against opposite sides of the thin hooked portion 25 of the dial element D.

As is well known, the needles N of a fine gauge circular hosiery knitting machine, of the type adapted to knit fine gauge ladies hosiery, are placed very close together since there are 400 or more needles around a needle cylinder which is about 3 to 4 inches in diameter. Thus, the outer end portion 25 of the dial element D must be very thin in order to pass between immediately adjacent active knitting needles to pick up the yarn at each knitting station. For example, it has been found that the outer end portion 25 of the dial element D should be on the order of about 0.012 of an inch while the thickened inner portion 24 is preferably on the order of about 0.032 of an inch. Thus, the outer portion 25 is less than half the thickness of the inner portion 24 of the dial element D.

As mentioned heretofore, the outer end of the dial element D is provided with a sharpened end 26 (FIGS. 4 and 5) so that the outer end of the dial element D will more easily penetrate and pass between immediately adjacent needles as it is moved outwardly in a radial direction. The radial position of the dial plate 20 may be adjusted to align the dial element D with a space between any pair of adjacent needles where it is desired to form a slit in the fabric.

METHOD OF OPERATION In forming a ladies fine gauge hosiery blank, suitable for use as a panty hose blank, it is the usual procedure to start at the top of the blank and knit to the toe end. Any suitable type of make-up can be formed on the top of the panty hose blank and it may be described to begin operation of the fabric slitting device during the formation of the make-up courses or the device may begin operation at any later point in the knitting of the tubular sleeve or blank. To begin operation of the slitting device, it is only necessary to lower the vertically movable cam 34 to the operative position so that it engages the operating butt 31 to project the dial element D outwardly in advance of the main knitting station 10. The outer hooked end 25 of the dial element D moves outwardly beyond the circle of needles N and between immediately adjacent needles to remain in this outer position as it passes the feed finger 15 at the main knitting station 10. As the needles immediately adjacent opposite sides of the dial element D pick up the yarn 3-1 in their hooks and draw the same downwardly, the yarn 3-1 is drawn down over the hooked outer portion 25 and held thereon as stitch loops are formed on the needles adjacent opposite sides thereof.

The dial element D remains in the outer position with the outer hooked end portion 25 between the same adjacent needles as it passes the second knitting station 11 to pick up and fonn a held loop of the yarn B-2. Held yarn loops are also formed on the dial element D as it passes the third and fourth knitting stations l2, 13 so that four yarn loops are held on the outer hooked portion 25 after the dial element D passes the fourth knitting station. The operating butt 31 then engages the cam portion 33 to draw the dial element D inwardly between the fixed blade elements 40, 41 so that the outer cutting edges 40a and 41a engage and cut the loops held on the hooked portion 25 and form a walewise slit in the fabric and along a line of sinker loops.

As the operating butt 31 again engages the cam 34, the dial element D is again moved outwardly in position to pick up yarn loops at each of the knitting stations. This slitting operation may be continued for any number of predetermined courses of knitting and is terminated by simply raising the vertically movable cam 34 to an inoperable position so that the butt 30 of the dial element D is not engaged thereby. When the cam 34 is raised to inoperative position, the dial element D remains in an innermost position with the butt 31 engaging the outer peripheral edge of the inner cam ring 29 so that it will engage the cam portion 32 during the first rotation after cutting is completed, to impart a slight outward movement of the dial element D and thereby release any yarn ends which might be caught or trapped between the dial element D and the cutting edges 40a, 41a of the fixed blade elements 40, 41.

Since all the needles have been active, regular knitting may continue on all of the needles after the slit has been formed in the panty hose blank without any danger of forming drop stitches or the like. During the knitting of the remainder of the panty hose blank, the dial element D remains in an innermost or inactive position so that its outer free end is inside the circle of needles N and therefore it does not interfere with the knitting of the fabric.

In the drawings and specification there has been set forth a preferred embodiment of the invention and although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation.

I claim:

1. A method of slitting a seamless tubular fabric in a walewise direction as the fabric is being knit on a circular knitting machine having a rotating needle cylinder, needles supported for vertical movement in said cylinder, at least one knitting station where yarn is fed to said needles, a dial plate rotating with said needle cylinder and at least one yarn supporting dial element supported for radial movement in said dial plate, said method comprising the steps of i a. projecting said dial element outwardly beyond the needle circle and between said needles at said knitting station to engage a yarn between immediately adjacent needles and hold the same as the needles are drawn down on adjacent sides thereof to form stitch loops,

b. maintaining the yarn on the needles at each side of said dial element, and

c. cutting the yarn held on said dial element at a location spaced from said knitting station to provide the walewise slit in the fabric.

2. A method according to claim I wherein the knitting machine includes a plurality of knitting stations, and including the step of maintaining said dial element in the outward position at each knitting station to engage and hold a yarn loop at each knitting station, and cutting all held yarn loops at a location spaced between the first and last knitting stations.

3. In a circular knitting machine having a rotating cir-' cle of needles, at least one knitting station having yarn feeding means and being positioned closely adjacent said circle of needles, the combination therewith of means for slitting tubular fabric in a walewise direction as the fabric is being knit on said machine, saidslitting means comprising a. a yarn holding dial element supported inside of said needle circle and rotating in timed relationship to rotation of said needle circle, said dial element being supported for radial movement and including a hooked outer end portion,

b. first cam means positioned in advance of said knitting station for moving said dial element outwardly beyond said circle of needles and between immediately adjacent needles to engage the yarn at said knitting station and to hold the yarn while it is knit on needles adjacent opposite sides of said yarn holding dial element, and c. means spaced from said knitting station for cutting the yarn held on said dial element and to provide the walewise slit in the fabric. 4. In a circular knitting machine according to claim 3 wherein said cutting means includes a fixed yarn cut ting blade positioned adjacent at least one side of said dial element and including an outer cutting edge resiliently urged into engagement with said one side of said dial element, and second cam means spaced from said knitting station for imparting inward radial movement to said dial element to bring the yarn loop held in said hooked outer end portion into engagement with said fixed cutting blade and to thereby sever the held yarn.

5. In a circular knitting machine according to claim 4 wherein said cutting means includes a fixed cutting blade positioned on each side of said dial element, and means resiliently urging said fixed cutting blade elements inwardly against opposite sides of said dial element.

6. In a circular knitting machine according to claim 4 wherein the outer portion of said dial element, including said hooked outer end, is less than one-half as thick as the inner end portion of said dial element, and wherein the outer terminal end of said hooked portion is beveled on opposite sides to provide an outer sharpened end to aid in directing said dial element between immediately adjacent needles.

7. In a circular knitting machine according to claim 5 including a dial plate rotating in timed relation with said needle circle and having a radially extending groove therein, the inner portion of said groove being substantially the same thickness as the inner portions of said hooked dial element and said pair of adjacent fixed cutting blade elements, the outer portion of said groove being widened to provide a space between opposite side edges of said dial element, and the outer end por tions of said fixed cutting blade elements being bent outwardly and then inwardly and having sharpened outer terminal end portions resiliently engaging opposite sides of said hooked outer portion of said dial element to cut held loops drawn inwardly by said hooked outer portion of said dial element.

8. In a circular knitting machine according to claim 7 wherein said first cam means comprises a cam supported for vertical movement between a lowered operative position and a raised inoperative position, said slitting means being rendered inoperative upon said cam being raised to said inoperative position.

9. In a circular knitting machine according to claim 8 including third cam means positioned in advance of said first cam means for imparting sufficient outward movement to said dial element to release any yarn trapped between said dial element and said fixed cutting blades, said third cam means being operable upon movement of said first cam means to said raised inoperative position, and said third cam means being operable to move said dial element outwardly to an intermediate position where it does not pass between adjacent needles and does not engage the yarn at said knitting statlOn. 

1. A method of slitting a seamless tubular fabric in a walewise direction as the fabric is being knit on a circular knitting machine having a rotating needle cylinder, needles supported for vertical movement in said cylinder, at least one knitting station where yarn is fed to said needles, a dial plate rotating with said needle cylinder and at least one yarn supporting dial element supported for radial movement in said dial plate, said method comprising the steps of a. projecting said dial element outwardly beyond the needle circle and between said needles at said knitting station to engage a yarn between immediately adjacent needles and hold the same as the needles are drawn down on adjacent sides thereof to form stitch loops, b. maintaining the yarn on the needles at each side of said dial element, and c. cutting the yarn held on said dial element at a location spaced from said knitting station to provide the walewise slit in the fabric.
 2. A method according to claim 1 wherein the knitting machine includes a plurality of knitting stations, and including the step of maintaining said dial element in the outward position at each knitting station to engage and hold a yarn loop at each knitting station, and cutting all held yarn loops at a location spaced between the first and last knitting stations.
 3. In a circular knitting machine having a rotating circle of needles, at least one knitting station having yarn feeding means and being positioned closely adjacent said circle of needles, the combination therewith of means for slitting tubular fabric in a walewise direction as the fabric is being knit on said machine, said slitting means comprising a. a yarn holding dial element supported inside of said needle circle and rotating in timed relationship to rotation of said needle circle, said dial element being supported for radial movement and including a hooked outer end portion, b. first cam means positioned in advance of said knitting station for moving said dial element outwardly beyond said circle of needles and between immediately adjacent needles to engage the yarn at said knitting station and to hold the yarn while it is knit on needles adjacent opposite sides of said yarn holding dial element, and c. means spaced from said knitting station for cutting the yarn held on said dial element and to provide the walewise slit in the fabric.
 4. In a circular knitting machine according to claim 3 wherein said cutting means includes a fixed yarn cutting blade positioned adjacent at least one side of said dial element and including an outer cutting edge resiliently urged into engagement with said one side of said dial element, and second cam means spaced from said knitting station for imparting inward radial movement to said dial element to bring the yarn loop held in said hooked outer end portion into engagement with said fixed cutting blade and to thereby sever the held yarn.
 5. In a circular knitting machine according to claim 4 wherein said cutting means includes a fixed cutting blade positioned on each side of said dial element, and means resiliently urging said fixed cutting blade elements inwardly against opposite sides of said dial element.
 6. In a circular knitting machine according to claim 4 wherein the outer portion of said dial element, including said hooked outer end, is less than one-half as thick as the inner end portion of said dial element, and wherein the outer terminal end of said hooked portion is beveled on opposite sides to provide an outer sharpened end to aid in directing said dial element between immediately adjacent needles.
 7. In a circular knitting machine according to claim 5 including a dial plate rotating in timed relation with said needle circle and having a radially extending groove therein, the inner portion of said groove being substantially the same thickness as the inner portions of said hooked dial element and said pair of adjacent fixed cutting blade elements, the outer portion of said groove being widened to provide a space between opposite side edges of said dial element, and the outer end portions of said fixed cutting blade elements being bent outwardly and then inwardly and having sharpened outer terminal end portions resiliently engaging opposite sides of said hooked outer portion of said dial element to cut held loops drawn inwardly by said hooked outer portion of said dial element.
 8. In a circular knitting machine according to claim 7 wherein said first cam means comprises a cam supported for vertical movement between a lowered operative position and a raised inoperative position, said slitting means being rendered inoperative upon said cam being raised to said inoperative position.
 9. In a circular knitting machine according to claim 8 including third cam means positioned in advance of said first cam means for imparting sufficient outward movement to said dial element to release any yarn trapped between said dial element and said fixed cutting blades, said third cam means being operable upon movement of said first cam means to said raised inoperative position, and said third cam means being operable to move said dial element outwardly to an intermediate position where it does not pass between adjacent needles and does not engage the yarn at said knitting station. 